Mirror for changing the geometrical form of a light beam

Abstract

The invention is directed to a mirror having mutually adjacent segments defined by a body such as a cone, sphere, toroid, paraboloid or ellipsoid having a line focus. The segments are displayed in stepwise manner axially or parallelly laterally to suppress interference or for forming an intensity profile.

What is claimed is: 
     
       1. A mirror for changing the geometric form of a laser light beam reflected onto an object having a surface region thereon which has a line-shaped to strip-shaped configuration, the mirror comprising: body means having a plurality of mirror surface segments formed therein with each of said mirror surface segments being a portion of a body defining a surface of revolution;   said surfaces of revolution defining respective rotation axes which are at least approximately superposed on said surface region of said object;   said mirror surface segments having respective sizes selected so as to cause respective zones of said light beam to simultaneously impinge on several of said mirror surface segments;   said mirror surface segments being formed and positioned relative to each other so that each of said zones is reflected only once by the surface segment corresponding thereto and is directed onto said region of said object such that the laser light of all of said zones is at least partially superposed in said surface region so as to obtain a concentrated illumination thereof for performing work on said object; and,   said mirror surface segments being spatially offset one from the other.   
     
     
       2. The mirror of claim 1, said axes conjointly defining a single axis common to all of said mirror surface segments; and, said mirror surface segments being offset stepwise one from the other along said axis. 
     
     
       3. The mirror of claim 1, said mirror surface segments being arranged relative to each other so as to cause said rotation axes of the respective surfaces of revolution to be offset laterally one from the other. 
     
     
       4. The mirror of claim 3, said surface region of said object being strip-shaped and said surface segments being positioned with a pregiven spacing for each of said rotation axes so as to cause a specific intensity profile to be generated perpendicular to said rotation axes on said region of said object. 
     
     
       5. The mirror of claim 1, said mirror being assembled from separate body means for each of said mirror surface segments to a compact component. 
     
     
       6. The mirror of claim 1, said body means comprising a single part defining said plurality of mirror surface segments. 
     
     
       7. The mirror of claim 1, said mirror surface segments all having shaped different from each other. 
     
     
       8. The mirror of claim 1, said surfaces of revolution being selected from the group comprising a cone, sphere, toroid, ellipsoid and paraboloid. 
     
     
       9. The mirror of claim 1, wherein said mirror is a precision diamond turned piece. 
     
     
       10. A method for treating an object with a mirror for changing the geometric form of a light beam of a laser reflected onto the object having a surface region thereon which has a line-shaped to strip-shaped configuration, the mirror including: a plurality of segments formed on rotation body means; body means having a plurality of mirror surface segments formed therein with each of said mirror surface segments being a portion of a body defining a surface of revolution; said surfaces of revolution defining respective rotation axes which are at least approximately superposed on said surface region of said object; said mirror surface segments having respective sizes selected so as to cause respective zones of said light beam to simultaneously impinge on several of said mirror surface segments; said mirror surface segments being formed and positioned relative to each other so that each of said zones is reflected only once by the surface segment corresponding thereto and is directed onto said region of said object such that the laser light of all of said zones is at least partially superposed in said surface region so as to obtain a concentrated illumination thereof for performing work on said object; and, said mirror surface segments being spatially offset one from the other; the method comprising the step of positioning said mirror in said beam for irradiating the object stripwise.